[TOC] # FCC-ee flavour WG1 (b-rare-decay WP1) ## Material and links - [ESPPU-2025/2026](https://indico.cern.ch/event/1439855/contributions/6461584/attachments/3045959/5381919/FCC_PED_ESPPU_Flavour_310325_submit.pdf) "Prospects in flavour physics at the FCC" - J. F. Kamenik, A. Lusiani, S. Monteil, G. Wilkinson - [US Snowmass process](https://arxiv.org/abs/2203.06520) section "8.1 Decays of b-flavored hadrons" (from Wolfgang et al.) - [Time-Dependent Precision Measurement of B0s→ϕμ+μ− Decay at FCC-ee](https://arxiv.org/abs/2506.08089) - Tsz Hong Kwok, Zachary Polonsky, Valeriia Lukashenko, Jason Aebischer, Ben Kilminster - [Precision Tests in b→sℓ+ℓ− (ℓ=e,μ) at FCC-ee](https://arxiv.org/abs/2503.22635) - Marzia Bordone, Claudia Cornella, Joe Davighi - [New Strategies for New Physics Search with Λb→Λνν¯ Decays](https://arxiv.org/abs/2501.10652) - Wolfgang Altmannshofer, Sri Aditya Gadam, Kevin Toner - [Prospects for searches of b→sνν¯ decays at FCC-ee](https://arxiv.org/abs/2309.11353) - Yasmine Amhis, Matthew Kenzie, Méril Reboud, Aidan R. Wiederhold - [Prospects of searches for invisible B-meson decays at FCC-ee](https://arxiv.org/abs/2508.04471) - P. Alvarez Cartelle, M. Kenzie, R. Mangrulkar, A. R. Wiederhold, E. Wood - [Constraints on New Physics from decays of polarized Lambda_b^0 baryons at the FCC-ee](https://arxiv.org/abs/2510.02225) - Anja Beck, Mero Elmarassy, Asher Sabbagh, Michal Kreps, Eluned Smith - [Prospects for B_c^+ -> tau^+ nu_tau at FCC-ee](https://arxiv.org/abs/2105.13330) - Yasmine Amhis, Marie Hartmann, Clément Helsens, Donal Hill, Olcyr Sumensari ---- ## Presentations of studies: To be filled with studies done but not documented in papers or existing public documents (just on slides ?) - [K*tau tau](https://indico.cern.ch/event/1401678/contributions/5892282/attachments/2840027/4963971/Talk_TM_18-04-2024.pdf) studies ongoing Clermont ## Useful links Studies documented in [github webpage](https://hep-fcc.github.io/FCCeePhysicsPerformance/ ) - [flavour section](https://hep-fcc.github.io/FCCeePhysicsPerformance/case-studies/flavour/) --- ## Received mails / interested people ### Armin Ilg + PhD (Jona Dilg) [Zurich UTH] ``` Dear Rare Decays conveners I had a chat with Stéphane Monteil last week about his past fast simulation study of B0 -> K*0 tau+ tau- and he told me to contact you on the continuation of the study of this process for FCC-ee. Together with my PhD student Jona Dilg (in cc), we plan to study this process in more detail in full simulation, to drive the development of the vertex detector, which is crucial for this process. Are you aware of other people currently interested in such a study besides Stéphane? We’d greatly like to collaborate with others in the flavour community on this. We’ll anyway also be at the flavour workshop to discuss this in more detail. Thank you and kind regards, Armin ``` ### Radoslav Marchevski + PhD (Tobias Monnard) + Xunwu Zuo (PostDoc) [EPFL] ``` Dear Rare Decays conveners, I’m contacting you to let you know what the plans to study rare flavour processes at EPFL are. Me and my colleague, Lesya Shchutska (in cc) are working with two PhD students and a postdoc in our group on feasibility studies for several rare decays. We are at present focusing on decays with taus in the final states and looking for ways to tag taus at FCCee. Below you can find a list of processes that we are pursuing: 1. Bs to tau tau 2. Bc/B+ to tau nu We will get involved in other decays in the future but that is the status at the moment. Best regards, Rado & Lesya ``` ### Gianluca Inguglia [MBI Vienna] contacted Wolfgang a while ago: ``` I am writing regarding FCC. [...] I see you are in charge of the rare decays for the flavour studies for FCC? I registered for the November workshop at CERN currently planning to follow remotely. I just wanted to let you know that I could consider contributing to some studies, should it be needed. ``` # Workshop [link](https://indico.cern.ch/event/1588013/timetable/)